One advantage Cialis has over Viagra and Levitra is its What if I am taking other drugs? Oral medicine for ED also might not be safe or work well if you have: Very low blood pressure, called hypotension, or uncontrolled high blood pressure, called hypertension. What should I do if I forget a dose? How oral medicines differ Each oral medicine for ED has a slightly different chemical makeup.The drug comes in low-dose versions that can be taken daily. This means you can have sex at any time, rather than needing to take a pill from time to time as needed like other ED brands. The starting dose for daily-use Cialis is milligrams (mg). If that doesn’t work, you can increase your daily dose up to 5 mg. Prescription needed: yes Dosage: 5 mg Usage: take as needed or daily at a low dosage GET STARTED WITH HIMS MNT ‘s review At Hims, Cialis is available as: Daily . Side Effects. Headache, stomach upset, back pain, muscle pain, stuffy nose, flushing, or dizziness may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly. To.